main() {
    int i,j;

    input i;

    switch (i) {
		case 1:
			j = i + 1;
			output j;
			break;

		case 2:
			j = i + 2;
			output j;
			break;

		case 3:
			j = i + 3;
			output j;
			break;

		default:
			output "not 1 2 3";
			break;
    }
	output "\n";
}
